Picosecond laser welding of optical to structural materials

We report on recent progress to develop an industrially relevant, robust technique to bond highly dissimilar materials using
an ultrashort pulsed laser micro-welding technique. Tight focusing of light from a picosecond (ps) pulsed laser (in our case a
5.9ps, 400kHz Trumpf laser operating at 1030nm) at, close to, the interface between two materials allows for simultaneous heating of both. This absorption rapidly, and locally, heats the material leading to plasma formation from both materials.
With suitable surface preparation this plasma can be confined to the interface region where it mixes, cools and forms a true weld between the two materials. In this presentation I will provide an overview of the ultrashort laser welding process and concentrate on our recent results. Results are presented for fused silica glass to aluminium, copper and stainless steel; borosilicate glass to silicon; and sapphire to stainless steel.